Comments about Nikon Nikon MB-40 Multi Power Battery Pack for the F6 Auto Focus Camera.:

The MB-40 looks and feels solidly built and well designed and has performed admirably for me. I haven't exactly be slogging through jungles or wandering on camel-back through deserts with it, but it seems like it'd be up to the task if called upon.

One of the best things about the F6/MB-40 combo is that it allows me to use the same type of battery (EN-EL4) in my film gear that I use in my digital Nikon bodies, greatly simplifying the amount of gear I need to haul around. And having the option of powering the camera using standard AA (LR6) cells is a bonus.

On the down side, the MB-40 adds a fair amount of weight (depending on the type of batteries used) and bulk to the F6, though this can help to balance things a bit when hand-holding longer lenses. It is also quite expensive and doesn't come with the BL-3 cover necessary to use the EN-EL4 lithium-ion battery.